I have exactly the same problem.
I have tried all suggested solutions, but still cannot edit any projects (I have tried a new, empty project as well as editing existing projects).

The only option left would be a complete reinstall of the game (again), however I am reluctant to do this, because it is becoming the default solution to all problems.
It appears that the devs need to take a good look at the "force verifying" option, because apparently this function is not working properly.

OK, if you've tried all of the suggestions offered above and things still don't work for you, a reinstall is probably your best option.

Steam should be providing the current build. If it didn't provide the current build, you'd get a version mismatch error and couldn't log in to the game. However, I know nothing about how it delivers the game or how long it would take.

OK, if you've tried all of the suggestions offered above and things still don't work for you, a reinstall is probably your best option.

Steam should be providing the current build. If it didn't provide the current build, you'd get a version mismatch error and couldn't log in to the game. However, I know nothing about how it delivers the game or how long it would take.

I'm sorry I can't be of more help.

Unfortunately Steam no longer provides a complete download of the game.
I cleaned out the local game files and started to reinstall the game, and all I got were ~150 MB. So all that is delivered by Steam is some version of the launcher which then updates itself twice. I then have to download the rest of the game (~12GB) in the launcher.

Of course this is exactly what I wanted to avoid because for me downloading a game from Steam is several times faster than any other platform I know.

Update: Reinstalling the game did not help, after 20 minutes of waiting I still only get "Waiting for editing server to start up and patching Foundry updates". CPU and network usage are stuck at 0-1%, so the game is not doing anything. Memory usage is 700.600 K and not moving either.

Unfortunately Steam no longer provides a complete download of the game.
I cleaned out the local game files and started to reinstall the game, and all I got were ~150 MB. So all that is delivered by Steam is some version of the launcher which then updates itself twice. I then have to download the rest of the game (~12GB) in the launcher.

Of course this is exactly what I wanted to avoid because for me downloading a game from Steam is several times faster than any other platform I know.

Update: Reinstalling the game did not help, after 20 minutes of waiting I still only get "Waiting for editing server to start up and patching Foundry updates". CPU and network usage are stuck at 0-1%, so the game is not doing anything. Memory usage is 700.600 K and not moving either.